|Stonecipher, Clinton - Clint|
|THACKER, ERIC - Utah State University|
|RALPHS, MICHAEL - Retired ARS Employee|
Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/22/2018
Publication Date: 3/1/2019
Citation: Stonecipher, C.A., Thacker, E., Welch, K.D., Ralphs, M.H., Monaco, T.A. 2019. Long-term persistence of cool-season grasses planted to suppress broom snakeweed, downy brome, and weedy forbs. Rangeland Ecology and Management. 72(2):266-274. https://doi.org/10.1016/j.rama.2018.10.008.
Interpretive Summary: Invasive plants are spreading throughout arid and semi-arid rangelands of western North America. Long-lived perennial plants that can persist for long periods under harsh environmental conditions are needed to compete with invasive species. Crested wheatgrass, pubescent wheatgrass, and western wheatgrass persisted at two locations in Utah for greater than a 12 year period. The three cool-season grasses were able to compete with downy brome and weedy annual forbs and can be used in rangeland restoration.
Technical Abstract: Invasive plants are spreading throughout arid and semi-arid rangelands of western North America. Long-lived perennial plants that can persist under harsh environmental conditions are needed to compete with invasive species. The objective of this study was to conduct a long-term evaluation on the persistence of several native and introduced grass species and evaluate the ability of these grasses to suppress/ prevent reinvasion of snakeweed, downy brome, and annual forbs. Seeding treatments comprised three introduced grasses, a mix of these introduced grass species, three native grasses, a mix of these native grass species, or forage kochia. The treatments were seeded into 3 by 15-m (10 by 50 ft) plots in October 2003. Frequency and biomass of seeded species, snakeweed, downy brome, other grasses, and annual forbs were measured in 2015 and 2017 at Howell, Utah and in 2015 and 2016 in Nephi, Utah. Seeded species were evaluated for frequency of stand persistence. Crested wheatgrass persisted at both locations (> 62%) along with the rhizomatous grass species, pubescent wheatgrass (> 66%) and western wheatgrass (> 73%). Russian wildrye was still present at Howell (29%) with very little remaining at Nephi (7%). Squirreltail frequency was 20% at Howell and 11% at Nephi. Bluebunch wheatgrass was no longer present at either location (< 1%). Forage kochia remained at Nephi (36%) with very little at Howell (3%). Downy brome was present at both locations and was suppressed relative to control plots, at Nephi, by crested wheatgrass and the introduced grass mix (< 9%). Downy brome was greater than 91% in all plots, at Howell, in 2017. In summary, crested wheatgrass, pubescent wheatgrass, and western wheatgrass were able to persist over 12 years at both locations.